Character mistake: After Stewie and Brian go to tell the past versions of themselves not to tell 1999 Brian about 9/11, Stewie then finds out that Brian then told 1999 Brian to write the Harry Potter novels. This would have been impossible because the first Harry Potter novel was written in 1997, 2 years before the time period Stewie and Brian arrive in.

Lois: Hello?Peter: I can't take the trash out today, I'm working late at the office.Lois: The caller ID says you're calling from the kitchen. In fact I can see you.Peter: [Edging sideways.] OK, can you see me now?Lois: No.Peter: Now I am at the office.

They're in the Clam complaining that they can't drink when they make the revelation that Brian can because he's technically 56. But Quagmire should be able to drink, as in a much earlier episode, he's revealed to be over 60.